Letters from the July 28, 2007, issue of Science News

Gyro Q & A

Doesn’t “Spinning into Control” (SN: 05/19/07, p. 312) on flywheels leave out a significant aspect: the gyroscope effects of a rotating large mass? Wouldn’t it be a benefit for moving installations (stabilization) and a problem for immobile installations?

Lee Hukill
Palo Alto, Calif.

In the article, the flywheels depicted appear to have vertical axles. I presume that this prevents inertial forces from being a problem when a vehicle using one of these systems changes direction. It would seem that such forces could be a real problem for a vehicle with a flywheel installed horizontally when it attempted to turn.

Perry F. Crabill Jr.
Winchester, Va.

Gas on gas?

In view of the extreme importance of atmospheric carbon dioxide, I would have expected the momentous conclusion that southern oceans aren’t absorbing the expected increased amount of CO₂, as well as the assertion that nutrient-enriched water absorbs CO₂ less effectively than leaner water does, to be confirmed by field observations. As presented, “Biological Hot Spots: Ocean eddies may not always lock away carbon” (SN: 5/19/07, p. 307) appears to represent nothing more than speculation.

Fredric M. Blum
Merion, Pa.

Maybe it’s about sex

As I read “When female chimps become baby killers” (SN: 5/26/07, p. 333), I wondered if the sex of the killed infant was determined. In a troop characterized as having a disproportionate number of females, could it be that the chimps are selectively killing females in an attempt to balance sexes in the group?

Eliza Gouverneur
Princeton, N.J.

A hole and the head

“Migraines in men linked to heart attack risks” (SN: 5/26/07, p. 333) states that although men who suffer from migraines are more likely to experience heart attacks, scientists have failed to find a biological mechanism linking them. Such a link seems to be suggested in an earlier Science News article, “A Gasping Heart” (SN: 4/7/07, p. 218), which states that a patent foramen ovale is linked to migraines and that that heart defect, combined with sleep apnea, can cause oxygen desaturation, which can be a factor in cardiovascular disease.

William A. Stephens
Earlysville, Va.